AU: Update status to DOWNLOADING only after receiving some bytes from server.

download_action.h

 // Copyright (c) 2009 The Chromium OS Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef CHROMEOS_PLATFORM_UPDATE_ENGINE_DOWNLOAD_ACTION_H__
 #define CHROMEOS_PLATFORM_UPDATE_ENGINE_DOWNLOAD_ACTION_H__
 
 #include <sys/types.h>
 #include <sys/stat.h>
 #include <fcntl.h>
@@ skipping 17 matching lines @@
 // be piped into a SplitFileWriter, which will direct it to the kernel
 // and rootfs partitions. If it's a delta update, the destination kernel
 // and rootfs should already contain the source-version that this delta
 // update goes from. In this case, the update will be piped into a
 // DeltaPerformer that will apply the delta to the disk.
 
 namespace chromeos_update_engine {
 
 class DownloadActionDelegate {
  public:
-  // Called before any bytes are received and periodically after
-  // bytes are received.
-  // bytes_received is the number of bytes downloaded thus far.
-  // total is the number of bytes expected.
+  // Called right before starting the download with |active| set to
+  // true. Called after completing the download with |active| set to
+  // false.
+  virtual void SetDownloadStatus(bool active) = 0;
+
+  // Called periodically after bytes are received. This method will be
+  // invoked only if the download is active. |bytes_received| is the
+  // number of bytes downloaded thus far. |total| is the number of
+  // bytes expected.
   virtual void BytesReceived(uint64_t bytes_received, uint64_t total) = 0;
 };
 
 class DownloadAction;
 class NoneType;
 
 template<>
 class ActionTraits<DownloadAction> {
  public:
   // Takes and returns an InstallPlan
@@ skipping 47 matching lines @@
   scoped_ptr<DirectFileWriter> rootfs_file_writer_;
 
   // Used to apply a delta update:
   scoped_ptr<DeltaPerformer> delta_performer_;
 
   // Pointer to the HttpFetcher that does the http work.
   scoped_ptr<HttpFetcher> http_fetcher_;
 
   // Used to find the hash of the bytes downloaded
   OmahaHashCalculator omaha_hash_calculator_;
-  
+
   // For reporting status to outsiders
   DownloadActionDelegate* delegate_;
   uint64_t bytes_received_;
-  
+
   DISALLOW_COPY_AND_ASSIGN(DownloadAction);
 };
 
 // We want to be sure that we're compiled with large file support on linux,
 // just in case we find ourselves downloading large images.
 COMPILE_ASSERT(8 == sizeof(off_t), off_t_not_64_bit);
 
 }  // namespace chromeos_update_engine
 
 #endif  // CHROMEOS_PLATFORM_UPDATE_ENGINE_DOWNLOAD_ACTION_H__